package string;

public class StringDemo2 {
    public static void main(String[] args) {
        StringBuilder str = new StringBuilder("a");
        long start = System.currentTimeMillis();
        for (int i = 0; i < 10000; i++) {
            str.append("a");
        }
        long end = System.currentTimeMillis();
        System.out.println(end-start);
    }
}
